[manmardam]

the board are my build using L297/L298 and have input for STEP/DIR/ENABLE .
the step motor operation is:when a signal occur on STEP pin,ENABLE pin should be activated
to make motor to start and when the signal is lost,ENABLE pin should be low.

i've got no problem for STEP pins adjusment,and either for DIR pin,but for ENABLE pin,it is always high or low and i can not control it when needed.
when i set ENABLE pin to "1" the step motor works with mach3, but when there is no signal at STEP signal pin,the step motor is still active and it sounds like buzzzzzzzzzzzzz!!
how can i use L297/L298 to drive stepper,they have enable pin and i can not control this pin with my software.

best regard.

[Mongkol]

Hi manmardam,
I had ever used L297 to link with Mach3. I found L297 was not compatible with Mach3. Motor can rotate but the signal is not smooth. It sounds like L297 is can not catch the signal.You should change to use Pic-microcontroller better.Don't use L297 with mach3.

Mongkol

[manmardam]

signal is not smooth

Don't use L297 with mach3

unfortunatly i dont have oscop to see waveform. is the combination of L297 and L298 a good driver for cnc?
is there any better driver?

[manmardam]

this problem was occured previously.but no one explained HOW solved it .
plz help me solve it.

[kreutz]

The typical "frying eggs" noise is normal for the L297 (or L6506)/L298 combination, you should drive them only with Step/Dir, leaving the enable pin high, since when you disable the L298 the stepper holding torque is lost.

The sound is produced by chopper's subharmonic oscillation and is typical of all the chopper type controllers designed on the 80's and 90's when duty cycle exceeds 50%. There are techniques used to reduce or eliminate the sound, but they will require a more complex design.

Kreutz.

[manmardam]

in Kcam ,when CLOCK pin is HI = ENABLE pin is LOW
and when CLOCK is LOW= ENABLE in HI = turn motor

but in mach3, always ENABLE pin is HI or LOW
what?

[dmacaya]

We also have this same problem with the L297/L298 combination!

This week we will try to solve it by inverting via hardware (just with a transistor) the CLOCK signal and introducing it to the ENABLE pin in the L297 chip.

It is a shame that MACH3 has not more control on the output pins to generate an ENABLE signal for L297/L298 controllers.

Has somebody solved it someway?